[PATCH 4/7] KVM: x86: Lock arch specific vcpu ioctls centrally

[Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Signed-off-by: Avi Kivity <avi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/x86/kvm/x86.c |   41 ++---------------------------------------
 1 files changed, 2 insertions(+), 39 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eedb23b..8b9e5ec 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1531,16 +1531,12 @@ static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
 {
 	int i, idx;
 
-	vcpu_load(vcpu);
-
 	idx = srcu_read_lock(&vcpu->kvm->srcu);
 	for (i = 0; i < msrs->nmsrs; ++i)
 		if (do_msr(vcpu, entries[i].index, &entries[i].data))
 			break;
 	srcu_read_unlock(&vcpu->kvm->srcu, idx);
 
-	vcpu_put(vcpu);
-
 	return i;
 }
 
@@ -1788,7 +1784,6 @@ static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 	if (copy_from_user(cpuid_entries, entries,
 			   cpuid->nent * sizeof(struct kvm_cpuid_entry)))
 		goto out_free;
-	vcpu_load(vcpu);
 	for (i = 0; i < cpuid->nent; i++) {
 		vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
 		vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
@@ -1806,7 +1801,6 @@ static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 	r = 0;
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops->cpuid_update(vcpu);
-	vcpu_put(vcpu);
 
 out_free:
 	vfree(cpuid_entries);
@@ -1827,11 +1821,9 @@ static int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 	if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
 			   cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
 		goto out;
-	vcpu_load(vcpu);
 	vcpu->arch.cpuid_nent = cpuid->nent;
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops->cpuid_update(vcpu);
-	vcpu_put(vcpu);
 	return 0;
 
 out:
@@ -1844,7 +1836,6 @@ static int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 {
 	int r;
 
-	vcpu_load(vcpu);
 	r = -E2BIG;
 	if (cpuid->nent < vcpu->arch.cpuid_nent)
 		goto out;
@@ -1856,7 +1847,6 @@ static int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 
 out:
 	cpuid->nent = vcpu->arch.cpuid_nent;
-	vcpu_put(vcpu);
 	return r;
 }
 
@@ -2088,9 +2078,7 @@ out:
 static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
 				    struct kvm_lapic_state *s)
 {
-	vcpu_load(vcpu);
 	memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);
-	vcpu_put(vcpu);
 
 	return 0;
 }
@@ -2098,11 +2086,9 @@ static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
 static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
 				    struct kvm_lapic_state *s)
 {
-	vcpu_load(vcpu);
 	memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s);
 	kvm_apic_post_state_restore(vcpu);
 	update_cr8_intercept(vcpu);
-	vcpu_put(vcpu);
 
 	return 0;
 }
@@ -2114,20 +2100,15 @@ static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 	if (irqchip_in_kernel(vcpu->kvm))
 		return -ENXIO;
-	vcpu_load(vcpu);
 
 	kvm_queue_interrupt(vcpu, irq->irq, false);
 
-	vcpu_put(vcpu);
-
 	return 0;
 }
 
 static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
 {
-	vcpu_load(vcpu);
 	kvm_inject_nmi(vcpu);
-	vcpu_put(vcpu);
 
 	return 0;
 }
@@ -2147,7 +2128,6 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 	int r;
 	unsigned bank_num = mcg_cap & 0xff, bank;
 
-	vcpu_load(vcpu);
 	r = -EINVAL;
 	if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
 		goto out;
@@ -2162,7 +2142,6 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
 	for (bank = 0; bank < bank_num; bank++)
 		vcpu->arch.mce_banks[bank*4] = ~(u64)0;
 out:
-	vcpu_put(vcpu);
 	return r;
 }
 
@@ -2220,8 +2199,6 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
 static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
 					       struct kvm_vcpu_events *events)
 {
-	vcpu_load(vcpu);
-
 	events->exception.injected =
 		vcpu->arch.exception.pending &&
 		!kvm_exception_is_soft(vcpu->arch.exception.nr);
@@ -2246,8 +2223,6 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
 	events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
 			 | KVM_VCPUEVENT_VALID_SIPI_VECTOR
 			 | KVM_VCPUEVENT_VALID_SHADOW);
-
-	vcpu_put(vcpu);
 }
 
 static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
@@ -2258,8 +2233,6 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 			      | KVM_VCPUEVENT_VALID_SHADOW))
 		return -EINVAL;
 
-	vcpu_load(vcpu);
-
 	vcpu->arch.exception.pending = events->exception.injected;
 	vcpu->arch.exception.nr = events->exception.nr;
 	vcpu->arch.exception.has_error_code = events->exception.has_error_code;
@@ -2282,22 +2255,16 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 	if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR)
 		vcpu->arch.sipi_vector = events->sipi_vector;
 
-	vcpu_put(vcpu);
-
 	return 0;
 }
 
 static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
 					     struct kvm_debugregs *dbgregs)
 {
-	vcpu_load(vcpu);
-
 	memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
 	dbgregs->dr6 = vcpu->arch.dr6;
 	dbgregs->dr7 = vcpu->arch.dr7;
 	dbgregs->flags = 0;
-
-	vcpu_put(vcpu);
 }
 
 static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
@@ -2306,14 +2273,10 @@ static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
 	if (dbgregs->flags)
 		return -EINVAL;
 
-	vcpu_load(vcpu);
-
 	memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
 	vcpu->arch.dr6 = dbgregs->dr6;
 	vcpu->arch.dr7 = dbgregs->dr7;
 
-	vcpu_put(vcpu);
-
 	return 0;
 }
 
@@ -2325,6 +2288,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 	int r;
 	struct kvm_lapic_state *lapic = NULL;
 
+	vcpu_load(vcpu);
 	switch (ioctl) {
 	case KVM_GET_LAPIC: {
 		r = -EINVAL;
@@ -2471,9 +2435,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		r = -EFAULT;
 		if (copy_from_user(&mce, argp, sizeof mce))
 			goto out;
-		vcpu_load(vcpu);
 		r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
-		vcpu_put(vcpu);
 		break;
 	}
 	case KVM_GET_VCPU_EVENTS: {
@@ -2524,6 +2486,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		r = -EINVAL;
 	}
 out:
+	vcpu_put(vcpu);
 	kfree(lapic);
 	return r;
 }
-- 
1.7.0.4